An occlusion device delivery system and methods are provided in which an expandable coiled implant can be delivered using the delivery system. The system can comprise a catheter having a lumen extending between distal and proximal portions. The distal portion can have proximal and distal apertures extending through a wall of the catheter. The expandable coiled implant, which can be wound about the distal portion, can have a proximal section that extends within the proximal aperture and a distal section that can extend radially within the distal aperture. Further, the system can comprise an elongate member that extends through the lumen and engages and radially restrains the at least one of the proximal and distal sections within its respective aperture while engaged with the member.